Tool has always been an interesting band. They are definitely heavy, but not overly melodic. Live, frontman/singer Maynard James Keenan many times stands somewhat to the back while bassist Justin Chancellor and guitarist Adams are at the forefront of the stage. At no point during a Tool show will members of the band hint at individual charisma, but that is also the point.
Instead, Tool lets the music stand out a bit more and you aren't distracted by the band moving around much. Supporting the music is a fairly impressive light display and images that pop up on a big screen behind the band. The atmosphere is more symphonic than festive. Again, that's exactly how the band wants the show to seem.
Everything about Tool, from the records to the live performances, is well-conceived and painstakingly organized. To Tool acolytes, this is how things should be. They don't have to think or even feel, but instead they are just happy to be consumed by what surrounds them. Each musician in Tool is amazing so the music is extremely well played, but there is no jazz-like creativity and instead a Phillip Glass-type drone becoming a wall of sound.
Tool puts out great music but their shows aren't for everyone
If you love the music of Tool, something akin to an Ayn Rand novel in its rigidity, then going to a show will further enhance your feelings. The band doesn't make mistakes in their prog-like live material. There is no room for error in a Tool world. In Knoxville, TN on Friday night, the songs were tight and long (nothing wrong with that if the song warrants the length), like a metal version of the Grateful Dead.
The issue is the cost of the tickets. Does one want to spend at least $200 a pop for a band whose albums you could play on your record player at home while turning the volume up to 11 while you watch an Ingmar Bergman film with the sound muted and randomly having a disco ball hang above you that goes off from time to time (total cost of those three items maybe $50?) or would a person rather spend $200 - at least! - a seat on a band that brings something more personal to their shows?
As Slipknot frontman Corey Taylor told Revolver Magazine, "(Tool is) amazing at what they do, but when I go to a show, I want to see something as well. And because they're not as demonstrably active, I get bored." Exactly.
Again, Tool makes better music than most other bands ever could, and the band cares about the music they release (they aren't in the game solely for the records sells but to put something original into the world). But because concert tickets are so expensive in today's world, you might spend your money more on a band that makes the performance an attempt at personal connection, like Slipknot does.